title: Use of macroaggregated albumin lung perfusion scan to diagnose hepatopulmonary syndrome: a new approach.
abstract: OBJECTIVE
  We have reported that contrast echocardiography is a sensitive screening test for the hepatopulmonary syndrome (HPS). However, contrast echocardiography lacks specificity because many cirrhotic patients have positive study results with normal arterial blood gases and therefore do not fulfill criteria for HPS. The aim of this study was to assess the role of macroaggregated albumin lung perfusion scans (MAA scans) in the diagnosis of HPS.
  
  
  METHODS
  MAA scans were performed in 25 patients with HPS, 25 cirrhotic patients without HPS, and 15 hypoxemic subjects with intrinsic lung disease alone. An MAA shunt fraction was calculated from brain and lung counts.
  
  
  RESULTS
  MAA scan results were positive in 21 of 25 patients with HPS and negative in all controls. All 21 patients with positive MAA scans had PO2 values of <60 mm Hg. There was a strong inverse correlation between the degree of the MAA shunt fraction and arterial hypoxemia (r = -0.726).
  
  
  CONCLUSIONS
  A positive MAA scan result in cirrhosis is specific for the presence of moderate to severe HPS. We speculate that MAA scans may be particularly useful in evaluating the contribution of HPS to the hypoxemia in cirrhotic patients with intrinsic lung disease.
authors.affiliation: Division of Gastroenterology and Hepatology, Liver Center, University of Alabama at Birmingham, 35294-0007, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Abrams
authors.forename: N C
authors.initials: NC
authors.lastname: Nanda
authors.forename: E V
authors.initials: EV
authors.lastname: Dubovsky
authors.forename: M J
authors.initials: MJ
authors.lastname: Krowka
authors.forename: M B
authors.initials: MB
authors.lastname: Fallon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging / Q000209:etiology; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D008103:Liver Cirrhosis / Q000150:complications*; D008168:Lung / Q000098:blood supply / Q000000981:diagnostic imaging; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011659:Pulmonary Gas Exchange; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013577:Syndrome; D013668:Technetium Tc 99m Aggregated Albumin
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin